The present invention relates to binaural loudspeaker reproduction, and in particular to such a system wherein the crosstalk free listening point is provided anywhere on a pair of parallel vertical planes spaced apart a distance equal to the distance between respective ears of the human head.
The binaural sound reproduction systems which have hitherto been proposed accompany disadvantages in that the listener must be seated in a predetermined position with respect to the loudspeakers if he desires to hear sound which is free from interference resulting from the presence of acoustic crosstalk paths which are nonexistant in headphone reproduction. A prior art method involves the use of a first rightward speaker, a second rightward speaker spaced behind the first, a first leftward speaker and a second leftward speaker spaced behind the first leftward speaker. The first rightward speaker and the secone leftward speaker constitute an isosceles triangle with the listener's left ear so as to form a left-side vertical plane which is equidistant from these speakers and crosses the listener's left ear, and the first leftward speaker and the second rightward speaker constitute an isosceles triangle with the listener's right ear forming a right-side vertical equidistant plane crossing the listener's right ear. In so far as the listener's respective ears are positioned on the right and left equidistant planes, crosstalk components are cancelled. However, these equidistant planes are at an angle to each other so that the space in which the listener can enjoy crosstalk-free reproduction is severely limited.